This invention relates to harvesting machines, to harvesting machine assemblies, and in particular to retractable fingers in rotary augers in harvesting machine assemblies.
In harvester assemblies, it is common for the assembly to include a tubular crop converging auger which assists in transfer of crop material from the harvesting assembly into a feeder conveyor. Such crop converging auger commonly includes opposing spiral flights to assist such auger in moving the crop material from the ends of the harvesting assembly to the center of the harvesting assembly where the crop material is fed into the feeder conveyor. The central portion of the auger, forward of and in the vicinity of the feeder conveyor, is provided with a rotating finger assembly of extending and retracting fingers. In the finger assembly, a finger crank shaft is mounted inside the tube of the tubular auger, eccentric to the rotating auger tube, and is generally restrained against continuous rotation of such finger crank shaft.
Elongate intake fingers are journalled on the finger crank shaft for generally free rotation with respect to the generally fixedly-mounted crank shaft, whereby the fingers can freely rotate about the crank shaft while the crank shaft, itself, is not rotating. The intake fingers extend generally radially outwardly from the finger crank shaft, and generally outwardly of the auger, and generally extend radially outwardly of the auger tube through guide holes or slots in the side wall of the auger tube, or through guide bearings mounted to such holes or slots in the side wall of the auger tube. As the tube rotates, the rotational movement of the auger exerts force against the sides of the fingers, whereby the fingers are caused to rotate about the finger crank shaft. Since the finger crank shaft is eccentric with respect to the longitudinal axis of the auger tube, as the fingers rotate about the finger crank shaft, as forced by the side walls of the auger tube, the fingers appear to repeatedly move outwardly and inwardly of the auger as the auger rotates about its longitudinal axis. The finger crank shaft is so positioned within the auger that the intake fingers extend from the auger to engage crop material as the respective fingers are located toward the front of the assembly and moving downwardly to engage crop material, and retract inwardly of the auger as the fingers move upwardly and forward across the top of the auger. Such positioning of the finger crank shaft thus times extension and retraction of the intake fingers such that the intake fingers extend to engage and take in crop material which is on the assembly floor, and sweep such crop material under the auger, taking such crop material into the feeder conveyor which is behind the auger. As the fingers rise on the rear of the auger, the retraction of the intake fingers into the auger assist in releasing the crop material from the fingers and taking the crop material into the feeder conveyor.
A harvesting assembly must operate in a variety of soil and crop conditions. Such assembly is commonly positioned by the operator so as to be as close to the ground surface as possible, in order to harvest as much of the harvestable crop as possible. Further, a harvesting assembly is often operated at or near maximum capacity so as to gain as much production as possible during the harvest season, and while the crop is at peak value. With such a high incentive for the operator to operate the harvester at or near capacity, the harvester, including the conveying elements, and including the auger and fingers, are subjected to heavy and fluctuating loads. Because the harvesting assembly is often operated close to the surface of the ground, the platform commonly picks up extraneous, non-crop items from the soil, for example rocks, clods of dirt, scrap metal, and like detritus. Such extraneous material periodically finds its way to the central portion of the platform where the auger fingers may engage such extraneous field detritus.
While the fingers are engineered to process and handle the stresses imposed by the crop materials, including high levels of loading of the crop materials, the fingers are susceptible to being damaged or broken by the in advertent picking up and feeding of such extraneous detritus, particularly rock, from the surface of the soil. Such broken fingers may pass through the harvester and thereby damage the components of the harvester. In addition, the fingers are subject to regular abrasion from the dirt gathered in with the crop, as well as from the crop materials, themselves.
There is thus a relatively frequent need to remove and reinstall worn-out platform auger fingers, and to replace damaged or broken auger fingers.
It is an object of the invention to provide improved auger fingers which are less susceptible of being damaged.
It is another object of the invention to provide auger fingers which are less prone to separation of pieces from damaged or broken fingers.
It is yet another object of the invention to provide fingers which, when broken pieces do separate from the fingers, can pass through the harvester with less damage to other harvester components, or no damage to the other harvester components.
It is yet a further object to provide harvesting assemblies which incorporate therein improved auger fingers which are less susceptible of failure, and which do less or no damage to other harvester components when such fingers do fail.
An intake finger for use in a harvesting machine comprises a central longitudinal shaft made with polyester or polyurethane, and a sleeve overlying the central shaft and extending from a distal end of the shaft toward a proximal, mounting end of the shaft. The central longitudinal shaft is preferably fiber reinforced, to provide overall strength to the intake finger. The composition of the sleeve is selected for good abrasion resistance, and is generally selected from thermoplastic polyurethanes.
In a first family of embodiments, the invention comprehends an elongate intake finger for use with an intake portion of a harvesting assembly on a harvesting machine such as a combine, a haybine, a bailer, a corn picker, or the like. The intake finger has a length, and comprises a central longitudinal reinforced polymeric shaft, having an outer surface. The shaft has a proximal end and a distal end. The composition of the shaft comprises polymer selected from the group consisting of thermoset polyesters and thermoplastic polyurethanes. The finger also includes a sleeve made of sleeve material polymer, overlying the shaft, and extending, from a locus at or proximate the distal end of the shaft, along the length of the shaft, toward the proximal end of the shaft. The composition of the sleeve comprises a thermoplastic polyurethane composition.
In preferred embodiments, the composition of the sleeve comprises polyester-based thermoplastic polyurethane.
In preferred embodiments, the sleeve has a hardness of about Shore D-45 to about Shore D-70.
A preferred sleeve has an abrasion wear life, in crop harvesting use, of at least 200 hours.
A preferred embodiment of the finger includes a mounting aperture extending transversely into the shaft under the sleeve, the mounting aperture containing sleeve material which assists in mounting the sleeve to the shaft.
In preferred embodiments, the sleeve extends along about 50 percent to about 80 percent of the length of the shaft.
Further to preferred embodiments, the sleeve can be a first color readily distinguishable from a second color of the shaft whereby a user can readily distinguish by color when the sleeve is worn away to the extent that the finger should be replaced.
Some embodiments of the finger include a cap on the proximal end of the finger, the cap defining a first cross-section of the shaft plus the cap, along the length of the shaft, different from a second cross-section of the shaft displaced from the cap.
In highly preferred embodiments, the shaft comprises fiberglass-reinforced thermoset polyester and the sleeve comprises aromatic polyester-based thermoplastic polyurethane.
In a second family of embodiments, the invention contemplates a harvesting assembly, for use on a harvester. The harvesting assembly comprises a support structure; crop detachment apparatus such as a reciprocating cutter or corn ear plucking apparatus. The harvesting assembly further comprises an auger comprising a generally hollow cylinder having first and second ends, and a length between the first and second ends. Opposite hand flights extend from adjacent the first and second ends, at an outer surface of the cylinder, for conveying crop material toward a central section of the auger. The cylinder has apertures therein, extending to an interior cavity disposed inwardly of the cylinder. The harvesting assembly further comprises an intake finger assembly. The intake finger assembly comprises a plurality of fingers, and bearings mounting the fingers to a finger crankshaft in the cavity, for rotation of the fingers about the crankshaft. The finger assembly, including the crankshaft, cooperates with the cylinder to extend and retract the fingers through the apertures as the auger rotates about a central longitudinal axis. The fingers comprise reinforced polymeric shafts. The compositions of the shafts are selected from the group consisting of thermoset polyesters and thermoplastic polyurethanes. The fingers further comprise sleeves, made of sleeve material polymer. The sleeves overlie the shafts, and extend from loci at or proximate distal ends of the fingers remote from the crankshaft, toward the crankshaft, the sleeves comprising thermoplastic polyurethane compositions.